Established 2004

Ruddlesden geotechnical

Ruddlesden geotechnical provides ground investigation, geotechnical consultancy and contamination assessment services.

Based in Exeter, but covering the whole of the UK, albeit primarily concentrated in the South West, Ruddlesden geotechnical was formed in 2004.

Ruddlesden geotechnical works on behalf of a wide client base, including local, regional and national housing developers, housing associations, commercial developers, building contractors, structural and civil engineers, architects, building consultants, quantity surveyors, local authorities and private individuals.

Development projects range from single dwellings and extensions to large housing estates, multi-storey flats, offices, industrial units, roads, slopes, schools, hospitals and basements.

The services and projects listed on this web-site provide an indication of those undertaken by Ruddlesden geotechnical, but others are carried out. If your requirement is not readily identifiable on this web-site, please contact us as we may still be able to help you.

  • AGS
  • Constructionline
  • CSCS
  • SMAS
  • ECFC trust
  • Latest news

    25 Mar 2026

    BRE 365 Soakaway Testing

    Simon Ruddlesden was pleased to present at the AGS Annual Conference, to talk about BRE 365 soakaway testing, asking the question, though not necessarily providing the answer: Should we be carrying out BRE 365 soakaway testing in geologies where previous testing has shown soakaway/ infiltration drainage to be unsuitable? The BRE 365 soakaway test is widely accepted and requested as the field test that is to be carried out to assess the suitability of the ground for soakaway/ infiltration drainage. However, the test is not without danger, mainly due to working at height risks, and it is relatively wasteful of resources, including fuel and water. If previous testing results consistently and convincingly show that certain geologies are unsuitable for soakaway/ infiltration drainage, should a relatively unsafe and not particularly sustainable test be carried out? Using data from over 5,000 tests on more than 1,200 sites investigated by Ruddlesden geotechnical over the last 20 years, mainly in the South West, there is a clear and understandable correlation between unsuccessful tests and the underlying geology, where the underlying geology comprises predominantly lower permeability mudstones and clays, notably the Mercia Mudstone Group, Lias Group and Oxford Clay Formation, although there are a number of anomalies, which can usually be explained by a closer inspection of the local geology, including superficial deposits. More data and research will be required if regulators and designers are to accept that no testing is required in certain geologies. The presentation sparked an interesting discussion afterwards, and it is hoped that it will have inspired others to share their data and/ or offer technical support, to ultimately produce a map that provides confidence to regulators and designers that BRE 365 testing is not required in certain geologies. Please contact us directly if you would like to discuss this further.

    BRE 365 Soakaway Testing
    BRE 365 Soakaway Testing
  • Recent projects

    Ground Improvement, Shropshire

    To inform the design of an embankment for a proposed highway, as part of the residential redevelopment of a site in Shropshire, Ruddlesden geotechnical were instructed to undertake a geotechnical investigation and assessment. The geotechnical investigation comprised cable percussive boreholes, which encountered a succession of Alluvial soils, including peat, silt and clay to depths in excess of 10m depth. Analyses indicated that the surcharge of the embankment would consolidate the underlying soils by virtue of their low strength, which would likely affect the serviceability of the proposed highway. It was also considered that there would be an insufficient factor of safety on the global stability of the embankment. Ruddlesden geotechnical proposed that ground improvement be undertaken, for example by pre-surcharging the ground and installing drainage, to speed-up the consolidation of the underlying Alluvial soils, to reduce the amount of anticipated settlement in the long term to acceptable levels.

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  • Recent projects

    Temporary Works Excavation Stability Assessment, North Devon

    It was proposed to construct a retaining wall as part of the proposed redevelopment of a residential site in north Devon. Ruddlesden were commissioned to provide a method statement detailing precautions to be taken during excavations, with details of the support to be provided during temporary works and construction of the retaining wall. Whilst it was considered that one of the excavations could be safely graded back to a safe angle of repose to facilitate the construction of the retaining wall, where this was not possible, the soils and rock exposed in the excavation were retained by a proprietary geo-grid/ mesh pinned into the slope, to mitigate the risk of rock fall.

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